Given a string, your task is to reverse the string keeping the spaces intact to their positions.

Example 1:

Input:
S = "Help others"
Output: sreh topleH
Explanation: The space is intact at index 4
while all other characters are reversed.

Example 2:

Input: 
S = "geeksforgeeks"
Output: skeegrofskeeg
Explanation: No space present, hence the
entire string is reversed.

Your Task:
You don't need to read input or print anything. Your task is to complete the function reverseWithSpacesIntact() which takes the string S as input and returns the resultant string by reversing the string while keeping all the spaces intact.

Expected Time Complexity: O(|S|).
Expected Auxiliary Space: O(1).

Constraints:
1<=|S|<=10⁵